From: Michael Weller <michael@...>
Date: 2004-01-23T22:19:58+09:00
Subject: [BEGINNER] Usage of 'super'

Hi!
I have some experience with programming in other languages, but I'm new 
to Ruby.
Here's a problem I encoutered writing my first program:
I got these two classes, both classes are defined in the same file 
(let's call it "modA"):

<code>
class A
	def initialize
		#inits some instance variables
	end
end

class B < A
	def initialize(x, y)
		super
		@myX = x
		@myY = y
	end
end
</code>

If I create instances of B in the same file (!), everything is OK
(e.g.:
b = B.new('sth', 'anotherSth')
puts b.toS
).

But if create another file and 'include modA' and do the same all I get 
is this:
../blogdata.rb:23:in `initialize': wrong number of arguments(0 for 2) 
(ArgumentError)
	from ./blogdata.rb:23:in `new'
	from ./blogdata.rb:23:in `initialize'
	from ./blogdata.rb:32:in `initialize'
	from UI.rbw:5:in `new'
	from UI.rbw:5

So it seems like B is trying to pass the two params it received on to A. 
A doesn't define 'initialize' with two params to I get an error.
I looked in the "Ruby Man Docs" and on the syntax page the author states:
"the super invokes the method which the current method overrides. If no 
arguments given, arguments to the current method passed to the method."

My questions:
Can I change this behaviour? Do I need to introduce an "initialize(a,b)' 
in my A class? Why does it work if my code is written in the same file?

Lots of questions I'm sure somebody here can answer!

Thanks in advance,
	Michael